Systemic Functional Grammar (SFG) is a major linguistic theory, which has received special attention from researchers working in natural language generation. It was developed at the University of London by Michael Halliday, as a continuation of the work of his predecessors there, in particular that of J.R. Firth. This approach is therefore sometimes called ``Neo-Firthian linguistics'', or the ``London school of linguistics'' [Sampson 1980] (though both Firth and Halliday came from Leeds). [Steiner 1983] gives an excellent survey of the development of the theory. Here only a few key points in the growth of SFG will be mentioned.
Firth's predecessor at London, the anthropologist B.K. Malinowski made important contributions to early modern linguistics from an anthropological perspective. His view of ``meaning as function in context'' was inherited by Firth and Halliday. His analysis of different types of context, summarised in Figure 1.1 (from [Steiner 1983]), was the forerunner of Halliday's division of the functional areas of language into three general metafunctions (see Section 1.2.3).
J.R. Firth, the founder of modern British linguistics and the first Professor of General Linguistics in the UK, continued Malinowski's emphasis on a social and functional approach to language, while establishing linguistics as an independent discipline. It was Firth who began to use the word ``system'' in a new sense as a technical term, from which the name ``systemic grammar'' originated.
``The first principle of analysis is to distinguish between STRUCTURE and SYSTEM. Structure consists of elements in interior syntagmatic relation and these elements have their places in an order of mutual expectancy. ... Systems of commutable terms or units are set up to state the paradigmatic values of the elements.'' [Firth 1957]
Firth emphasized the need for linguistics to give equal importance to both the ``anatomy'' and ``physiology'' of language. These two aspects of language can be summarized in the list of contrasting pairs of Firthian linguistic terms in Figure 1.2.
Firth disagreed with the American structuralists of his time (led by Bloomfield), because they were concerned only with the ``anatomy'' of language. For the same reason Michael Halliday, Firth's pupil and successor at London, disagreed with the American formalists (led by Chomsky). Halliday is closer to the European functionalists, such as the Prague school, from whose theory of Functional Sentence Perspective he adopted the theme/rheme structure for his textual metafunction (see Section 1.2.3). In reaction to the dominant American schools, the Neo-Firthians stressed the ``physiology'' of language, not because the ``anatomy'' is unimportant, but in an attempt to redress the balance.
Whereas Firth's theory was often expressed in general terms, and his concrete examples were often fragmentary, Halliday developed a systematic and comprehensive theory of language, with a new terminology of its own. This theory, expounded in Halliday's many publications, became known as Systemic Functional Grammar. It was called ``systemic'' because of his development of detailed system networks (see Section 1.2.1) for many areas of English grammar, and for interesting areas of other languages. It was called ``functional'' because of his development of the theory of the ideational, interpersonal and textual metafunctions (see Section 1.2.3).
One unusual aspect of Halliday's theory is his non-acceptance of morphology as a separate level of language. He showed how inflections could be handled by systems and realizations in exactly the same way as clause structures. His approach here may have been influenced by the relatively restricted morphology in the two languages - English and Chinese - in which he specialised.
